refactor: introduce DefaultHistoryLimit constant for CronFederatedHPA

[anujagrawal699]

Description:
This PR introduces a DefaultHistoryLimit constant to replace the magic number '3' in CronFederatedHPA history limits.

Changes:

• Added DefaultHistoryLimit constant (value: 3) to define default history entries
• Updated GetCronFederatedHPASuccessHistoryLimits to use the constant
• Updated GetCronFederatedHPAFailedHistoryLimits to use the constant
• Improved test case names for better clarity and maintainability

What type of PR is this?
/kind cleanup
/kind documentation

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:
As suggested by @XiShanYongYe-Chang in #5768

Does this PR introduce a user-facing change?:

NONE

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Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 46.68%. Comparing base (064ccf1) to head (47528b4).

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Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5903      +/-   ##
==========================================
+ Coverage   46.67%   46.68%   +0.01%     
==========================================
  Files         663      663              
  Lines       54746    54746              
==========================================
+ Hits        25552    25560       +8     
+ Misses      27561    27554       -7     
+ Partials     1633     1632       -1     

Flag	Coverage Δ
unittests	46.68% <100.00%> (+0.01%)	⬆️

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[XiShanYongYe-Chang]

Thanks!
/lgtm
/approve

[karmada-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: XiShanYongYe-Chang

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